1. Enhanced methane emission from East-Siberian Arctic shelf: explanation hypothesis based on the analysis of bottom sediments, geological and paleo river morphology data

O. Anisimov, J. Strelchenko, V. Kokorev

The project objective is to develop the conceptual model that explains the enhanced methane emission at the shelf of the East Siberian Arctic Seas (ESAS). While results from mathematical modelling obtained under the preceding OSL-12-02 project suggest that thawing sub aquatic permafrost is not related to this process, observed enhanced fluxes of methane at selected locations on ESAS are yet to be explained by other mechanisms. In this project we shall explore the hypothesis, which suggests that observed methane venting is mostly bound to unfrozen bottom sediments surrounding fault zones and paleo river beds, while elsewhere on the inner ESAS shelf sediments remain frozen and impermeable for gases since the last glacial maximum. We shall check this hypothesis by collecting published geological and paleo data, including those on high resolution batimetry, analysis of genesis of the bottom sediment samples, and constructing the digital high resolution map of the fault zones and paleo river and lake beds at ESAS, which will be compared with locations of the hydrographic stations where enhanced methane fluxes have been observed. Our ultimate goal is to develop conceptual model that consistently explains the observed methane venting at ESAS in the context of changing climate and permafrost.

The Arctic Ocean is known to be very sensitive to environmental conditions. Its surface layer is a key component of the Arctic climate system, which constitutes the dynamical and thermodynamical link between the atmosphere and the underlying waters. It is obvious, that significant decreasing of the Arctic Ocean ice content over the recent years, as well as air temperature rising in the Arctic affect the state of the Arctic Ocean surface layer. A considerable increasing of the open water area in summer due to reduction of sea ice area would have led to an intensification of the interaction between the ocean and the atmosphere, and as a result, to the changes of the thermohaline state of the Arctic Ocean surface layer. Large anomalies of the thermohaline characteristics of the surface layer have been observed in recent years. The largest anomalies have been observed in the Canadian Basin, where significant freshening and warming of surface layer waters have occurred. Due to substantial climatic changes recently occurred in the Arctic, there is a question about the scenarios for the Arctic region future. The purpose of this study is to develop a statistical model of interannual variability of surface layer salinity in winter in the Arctic Ocean and the Arctic seas and obtaining prognostic salinity fields for 2011-2013.

The project is dedicated to estimating to understanding the processes of the unique poor studied water objects of the estuary zone of rivers. The main interest of the principal investigator is concentrating on the Lena River (East Siberia, Russia) as the biggest delta in the Arctic. The study is based on multiyear data from periodic literature and field data form regular Russian-German expeditions to the delta. The results have been showed different sources and role of different factors on formation of geochemical flow of the Lena River Delta. Concentrations of several dissolved and suspended substances from different water objects of the Delta (big and small delta channels, inflows from ice-complex and permafrost, lakes etc.) allow making first conclusions about a transformation of the geochemical flow from the top of the delta to the sea edge. The proposal will includes results of previous investigation and OSL's projects and going to be the finalization of the problem decision. The main results of the project will be included in the PhD thesis of principal investigator. This proposal is dedicated to support the last year of PhD program of the author.

4. Linking microbial community features and biodegradability of organic matter in Siberian arctic and sub-arctic permafrost-affecred soils

S. Evgrafova, V. Kholodilova, E. Vorozhtsova

Soils of high latitudes are of primary importance for the global carbon cycle. Given current circumstances of greenhouse gas-induced global warming, boreal and arctic regions are widely recognized as a critical component world resource, which by virtue of changing of a frozen level and a thermal regime of soils potentially becomes accessible to microbiological decomposition. However, the microbial communities as the drivers of carbon decomposition in Siberian permafrost-affected soils have been little studied so far. In this study we suppose to investigate the microbial community structure and activity of two Siberian regions: arctic (N 72°, E 126°) and sub-arctic (N 64°, E 100°) like representative areas of tundra and boreal forests. For detailed description of microbial communities structure we plan to use molecular-genetic methods and phylogenetic analysis. Basal respiration of soil microbial populations will be analyzed for assessment of heterotrophic respiration rates. This study comprises a comparison of geographically distant soil microbial communities in order to answer the question: how do the structure and activity of specific microbial populations depending on C-content and C\N ratio as well as temperature, freeze/thaw cycle and moisture conditions. The main goal of the project is to find out links between microbial community structure and activity and C/N composition of organic matter.

5. A sub-fossil Cladocera-based regional assessment of environmental and climate change in lakes and ponds of Arctic Russia

L. Frolova, O. Tumanov, L. Gafiatullina

Main objective of the study will be to assess the relationship between environmental change and subfossil Cladocera (Crustacea: Bracnchiopoda) distribution in space and time and reconstruction of past environmental variables and past climate change with using Cladocera remains. Sub-fossil cladocerans and environmental variables from Northern Ural and Northern Yakutia will be used to extend the calibration data set using ordination techniques, namely Detrended Correspondence Analysis (DCA) and Canonical Correspondance Analysis (CCA) for investigating the key environmental factor that is related with climate change structuring cladoceran community composition. Our study is directed towards developing an empirical model based on the relationships between Cladocerans taxa and abiotic variables (e.g., water chemistry, climate variables, etc.), particularly in terms of species optima to a measured variable. This inference model can then be used to reconstruct past changes of the abiotic variable of interest.

6. Foraminiferal-dominated benthic community from the eastern Kara Sea

S. Korsun, I. Kuznetsov, O. Knyazeva

The dominant organism in the benthic community off Taimyr Peninsula, the eastern Kara Sea, is a large soft-shelled foraminiferan with unexpectedly high biomasses of c. 40 g/m2. Utilizing the extensive environmental data obtained during the multidisciplinary expedition with RV Akademik Mstislav Keldysh, September 2011, we hope to understand which processes make this particular shallow area distinctive and how this unicellular organism sustains a high biomass in the oligotrophic Kara Sea.

7. Sources of the large-sized (>1 cm) dropstones and history of the ice/iceberg regime in the Arctic Ocean during the Quaternary time

A. Krylov, L. Ermakova, K. Kashirtseva

The project addresses the fundamental scientific problem – the reconstruction of ice/icebergs conditions/circulation in the central Arctic for the Quaternary time based on a comprehensive study of large-sized (> 1 cm) rock fragments (dropstones) and accommodating sediments. Samples (523 stones) were mainly selected during Polarstern-2008 expedition (ARKXXIII/3) to the Mendeleev Ridge areas; additional stones were retrieved during Arctica-2000 and Polarstern-2011 (ARK-XXVI/3) expeditions to the northern Mendeleev Ridge. We are considering a detailed study of large-sized fragments as a new approach for solving problem of paleo-ice circulation. Earlier works were based on study of heavy&light minerals, clays, iron oxides but results were generally contradicted each other. The main goal of this project is to clarify a reliable source of dropstones and paleo-trajectory of the ice/icebergs during the last 500-600 thousand years. It is also important to resolve the issue of the geological structure of the basement: if rock-fragments were not delivered by ice (icebergs), then they have a local origin. These ("local") samples are extremely important, taking into account the general lack of direct geological information on the structure of the basement in the Arctic Ocean.

The German/Russian expedition KuramBio (Kurile-Kamchatka Biodiversity Study) onboard of the R/V Sonne (summer 2012) to the Kurile-Kamchatka Trench and adjacent abyssal plain aimed to investigate the biodiversity of the benthos. Peracarida (Isopoda) and Polychaeta were the dominant macrobenthic taxa in species richness (about a quarter of all species). The material of previous expeditions onboard the R/V Vityaz (1949-1966) to that area is stored mainly in the Zoological Museum of St. Petersburg. For science and knowledge transfer between PhD students and their supervisors, exchange for progress is planned and our goals and objectives are: - exchange material in the Otto-Schmidt-Laboratory (OSL), - joint sorting and determination of polychaetes, isopods and cumaceans to genus level (OSL and later in the home institutions), - identification of the collected species (OSL and later in the home institutions), - description of at least one key species of polychaetes, isopods and cumaceans.

We hypothesize that natural transport and accumulation of the toxic heavy metals depend strongly on the environmental conditions, and thus climate-induced changes in the marine ecosystems may lead to significant alterations in their pathways and depositing. The study targets on key abiotic and biotic components of the White Sea ecosystems in regard to their accumulation capacity of the toxic heavy metals (Cd, Cr, Pb, As, Zn, Cu, Hg, etc.) and to assess the natural pathways of their transport through the studied biogeochemical system, with special regard to the areas representing the pristine environment in Kandalaksha Bay, 66ºN 38ºE. The study approaches in the first multidisciplinary investigation of mineral and organic (Corg, Norg) composition and heavy metals' concentrations in abiotic and biotic components in aerosols, snow, ice, freshwater (inflowing streams), suspended particulate matter, sediments, phyto- and zooplankton, macroalgae, key vertebrate (fish) and invertebrate (number of jellyfish, crustacean, mollusk, and echinoderm) species with special regard to the food web structure and matter fluxes. The study will result as numerical assessing of the heavy metals' pathways and accumulation rates through the abiotic and biotic components of sub-Arctic ecosystem and developing the scheme of their natural transport and deposition in the number of publications.

The main goals of current proposal are: (i) to establish regional peculiarities in species composition and biomass of sea-ice algal communities and ice-edge phytoplankton in the Laptev Sea at the beginning of productive period in March-April 2012, and (ii) to reveal dynamics and time-scale of the spring sea-ice algae and phytoplankton bloom in the southern part of the Laptev Sea, adjacent to the Lena River Delta, and its dependence of environmental changes. Approximately 30 phytoplankton samples and 90 samples from sea-ice cores, collected during TRANSDRIFT XX expedition to the southern Laptev Sea between March 19 and April 24, 2012, we plan to study. We aim to carry out detail study of species composition and biomass of microalgae in 7 ice cores phytoplankton communities at 6 sites. Episodically repeated water and sea-ice sampling, and measurements of hydrographic and sea-ice parameters, which were carried out during TRANSDRIT XX expedition, will allow us to reveal development of spring phytoplankton bloom at the beginning of productive period in the frontal zones formed between the fresh river water plume and saline marine waters. Proposed researches are the contribution to the joint Russian-German multi-disciplinary project "Laptev Sea System: The Eurasian Shelf Seas in the Arctic's Changing Environment - Frontal Zones and Polynya Systems in the Laptev Sea".

11. Tephra links for the terrestrial and marine deposits in the northwestern Pacific, northeastern Asian mainland and arctic regions

V. Ponomareva, A. Plechova, S. Krasheninnikov

Numerous tephra layers derived from highly explosive Kamchatka volcanic arc (northwest Pacific) are buried in various deposits on the Kamchatka Peninsula as well as in the adjacent seas and on Asian mainland as far as the Arctic coast. These layers directly link terrestrial and deep-sea stratigraphies permitting synchronizing and dating of major environmental changes. A goal of our interdisciplinary project is to geochemically fingerprint Quaternary tephra layers detected thus far in the northeastern Asia and correlate them to sources in Kamchatka and to marine cores in the northwest Pacific seas. Tephra samples will be characterized with the help of EMPA and single-shard LA-ICP-MS analysis of volcanic glass and minerals in GEOMAR; grainsize measurements, optical mineralogy and imaging of tephra particles will be performed in the OSL analytical lab. These data will be compared to our extensive database of tephra compositions from proximal volcanic deposits and marine cores around Kamchatka obtained during the KALMAR project. To extend our project into the Arctic seas we will explore the possibility of tephra presence in the Arctic sea cores. A complementary aspect of this study is that it will allow to access chronology and magnitude of the largest explosive eruptions in the Kamchatka arc.

Our project is aimed to detailed reconstruction of the plant cover evolution in the Laptev Sea hinterland linked to climatic oscillations in the Arctic during the Holocene through pollen record from the longest (844 cm) marine sediment core PS51/118-3 obtained from the eastern Laptev Sea continental slope. High-resolution AMS14C-dating showed that it covers the entire Holocene since about 11 cal. ka with almost 8 m of sediments accumulated during 11 to 9 cal. ka, thus allowing tracing the centennial-to decadal scale environmental changes during the early Holocene. By using this most continuous and adequately dated marine pollen record we intend to apply both BIOM and best modern analogue techniques for quantitative reconstruction of main plant formations (biomes) and variability of such climate parameters as annual precipitation, mean temperature of the warmest and the coldest month, heat and moisture indices and afterwards to compare the newly obtained results with previous pollen archives from the Laptev Sea shelf.

13. Assessment of forest fire effects on the hydrological regime in permafrost landscapes

O. Semenova, L. Lebedeva, N. Volkova

Fires in cold environment have both immediate and long-term impacts on the ecosystem due to their effects on surface energy, water balance, and underlying permafrost. The return period for wildfire is strongly influenced by current climate changes and human activities and is supposed to be significantly decreased in future. Though many studies of the effects of fire on the soil moisture, ground thermal regime and landscape characteristics driving hydrological processes in cold regions have been well documented, insufficient efforts were made to implement that comprehension into development of approaches to numerically estimate and project the effects of fire on environmental systems in future. The goal of the project would be the development of the approach to assess short- and long-term effects of forest fires on hydrological regime and its components in different permafrost environments of the Lena River basin. The investigation would be focused on effects of fire to the permafrost to quantify the post impacts of fire on (1) removing organic layer as an insulating material, (2) heat budget, (3) soil moisture characteristics, and (4) active layer dynamic. The evaluation of these agents will provide a better understanding of the relationship between burn severity and permafrost response and the effects on the hydrologic regime following wild fire. The project would combine the application of physically-based hydrological modelling and analysis and implementation of remote sensing data and products (Due Permafrost project). The project will logically continue the research conducted during the OSL Fellowships 2009–2011. It will be conducted by three young scientists, one completed PhD and two PhD students. The research would require collaboration and data exchange with the German colleagues, namely AWI and Jena University.

14. Past environmental transformation of the Laptev Sea continental margin since last deglacial times

E. Taldenkova, N. Chistyakova, Ya. Ovsepyan

The project is devoted to reconstruction of the postglacial environmental history of the Laptev Sea continental margin based on high-resolution records of lithological characteristics, IRD, microfossils (benthic and planktic foraminifers, ostracods), and stable isotope composition of foraminifers. It is aimed to finalize analytical research of long sediment cores from the eastern Laptev Sea continental slope and to start investigation of multicores from the Laptev Sea continental margin and adjacent part of Eurasian basin obtained in 2012 during ARK27-3 expedition aboard RV Polarstern. One of the main tasks of the project is preparation of the paper dealing with interregional comparison of postglacial environmental changes in the western and eastern Laptev Sea continental margin inferred from existing lithological (IRD, authigenic concretions) and microfossil records of AMS14C-dated cores PS2458 and PS51/154. It will address such important issues as variability in iceberg production, shifts in the position of the seasonal drift ice margin; timing and character of Atlantic-derived water inflows, freshwater inputs due to meltwater and/or fluvial discharge.